Read query string in js

query string.js

        //read query string in js
        function getParameterByName(name) {
            name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
            var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
        results = regex.exec(location.search);
            return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
        }